Electronic circuitry provides complex functionality that is proving ever more useful. One type of circuit is a sensor that senses a physical parameter to be measured (such as, for example, pressure), and generates an electrical sensor output signal that represents the measured parameter.
However, the electrical sensor output signal may vary with temperature even given a constant value of the physical parameter being measured. More specifically, temperature variations may cause the offset and gain of the electrical sensor output signal to vary thereby introducing temperature-induced inaccuracies into the sensor measurement.
Accordingly, sensor circuits often include a temperature compensation circuit within the signal path that follows the sensor. The temperature compensation circuit allows for some temperature compensation of the offset and gain of the electrical sensor output signal. Some temperature compensation circuits provide linear temperature compensation. However, the offset and gain of the electrical sensor output signal includes temperature-dependencies that are not linear. Stated another way, the electrical sensor output signal includes second and potential higher-order temperature dependencies. Accordingly, depending on the application, linear temperature compensation may not be sufficient to achieve the desired accuracy. Non-linear temperature compensation can help improve accuracy.
According to one conventional non-linear temperature compensation circuit, non-linearity is achieved by providing a piece-wise linear approximation of the actual temperature dependencies. However, a strict piece-wise linear approximation may not be desirable in some applications and/or for some sensors.